A month ago Joe Belfiore confirmed that in the future all Windows 10 PCs will be offered in the locked down Windows 10 S-mode, saying:

“Starting with the next update to Windows 10, coming soon, customers can choose to buy a new Windows 10 Home or Windows 10 Pro PC with S mode enabled.”

Given how unpopular the restrictions will be, however (with only Store apps allowed in S-mode) it is likely the majority of users who purchase PCs in S-mode unwittingly will want to switch to the unrestricted version of Windows.

It appears this will occur via a trip to the Microsoft Store, as spotted by Richard Hay.

Here is the "Switch out of S Mode" page in the Microsoft Store on Build 17134. Shows the free switching option that was previously announced. pic.twitter.com/SPT8MS52wB

This is similar to how one can buy an upgrade from Windows 10 Home to Windows 10 Pro in the Store, but for now, this appears to be free. It is notable that a full re-imaging is required to get back into S-mode once switched out.

It is not known how widespread the distribution of PCs shipped with S-mode on by default will be. Presumably, retailers will face a balance of pressure from Microsoft against the pushback from consumers unwilling to even make the trip to the Microsoft Store to restore their PC to full functionality.